1 /* $OpenBSD: mmap-sysctl-copyout.c,v 1.3 2021/12/13 16:56:50 deraadt Exp $ */ 2 3 #include <sys/types.h> 4 #include <sys/mman.h> 5 #include <sys/queue.h> 6 #include <sys/socket.h> 7 #include <sys/sysctl.h> 8 9 #include <netinet/in.h> 10 #include <netinet/tcp.h> 11 #include <netinet/tcp_seq.h> 12 #include <netinet/tcp_timer.h> 13 #include <netinet/tcp_var.h> 14 15 #include <err.h> 16 #include <fcntl.h> 17 #include <stdlib.h> 18 #include <limits.h> 19 #include <stdio.h> 20 #include <string.h> 21 #include <unistd.h> 22 23 #define FILE "sysctl-net.inet.tcp.stats" 24 #define CLIENT "/mnt/regress-nfs-client" 25 #define SERVER "/mnt/regress-nfs-server" 26 27 int 28 main(void) 29 { 30 char *p, path[PATH_MAX]; 31 int mib[] = { CTL_NET, PF_INET, IPPROTO_TCP, TCPCTL_STATS }; 32 u_int miblen = sizeof(mib) / sizeof(mib[0]); 33 struct tcpstat stats; 34 int fd; 35 size_t len; 36 ssize_t n; 37 38 /* 39 * Initialize file on NFS server. 40 */ 41 snprintf(path, sizeof(path), "%s/%s", SERVER, FILE); 42 if ((fd = open(path, O_RDWR|O_CREAT|O_TRUNC, 0777)) == -1) 43 err(1, "open write '%s'", path); 44 len = sizeof(struct tcpstat); 45 memset(&stats, 0, len); 46 if ((n = write(fd, &stats, len)) == -1) 47 err(1, "write"); 48 if ((size_t)n != len) 49 errx(1, "write not %zu: %zd", len, n); 50 if (close(fd) == -1) 51 err(1, "close read"); 52 53 /* 54 * Map file on NFS client and write sysctl net.inet.tcp.stats into it. 55 */ 56 snprintf(path, sizeof(path), "%s/%s", CLIENT, FILE); 57 if ((fd = open(path, O_RDWR)) == -1) 58 err(1, "open mmap '%s'", path); 59 p = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); 60 if (p == MAP_FAILED) 61 err(1, "mmap"); 62 if (sysctl(mib, miblen, p, &len, NULL, 0) == -1) 63 err(1, "sysctl get stat"); 64 if (len != sizeof(struct tcpstat)) 65 errx(1, "len not %zu: %zu", sizeof(struct tcpstat), len); 66 if (close(fd) == -1) 67 err(1, "close mmap"); 68 69 /* 70 * Read file from NFS server. 71 */ 72 snprintf(path, sizeof(path), "%s/%s", SERVER, FILE); 73 if ((fd = open(path, O_RDONLY)) == -1) 74 err(1, "open read '%s'", path); 75 if ((n = read(fd, &stats, len)) == -1) 76 err(1, "read"); 77 if ((size_t)n != len) 78 errx(1, "read not %zu: %zd", len, n); 79 if (close(fd) == -1) 80 err(1, "close read"); 81 82 return (0); 83 } 84